Reciprocating piston engine



Oct. 13, 1964 B. K. WOOLFENDEN 3,152,517

. RECIPROCATING PISTON ENGINE 3 Sheets-Sheet 1 Filed Feb. 15, 1963 FIG?)INVENTOR BRIAN K. WOOLFENDEN ATTORNEYS Oct. 13, 1964 a. K. WOOLFENDEN3,152,517

RECIPROCATING PISTON ENGINE Filed Feb. 15, 1965 s Sheets-Sheet 5 FIGS fr4,, I FIGIO FIG."

INVENTOR BRIAN K. WOOLFENDEN BY United States Patent 3,152,517RECIFRGCA'IING PISTON ENGINE Brian K. Wooitenden, Grafton, NFL, assignorto Air Froducts will Chemicais, Inc a corporation or Deiaware Filed Feb.15, 1963, Ser. No. 25%,731 I4 Ciairns. (Cl. 91-247) The presentinvention relates to reciprocating piston engines, more particularly ofthe type in which a gaseous fluid is expanded with the performance ofexternal work or is compressed by the performance of Work. The inventionwill be described and illustrated in one exemplary embodiment as anexpansion engine; however, it is to be expressiy understood that exceptas indicated in certain of the more specific claims, the invention isequally well adapted for embodiment in a compressor.

It is an object of the present invention to provide a reciprocatingpiston engine that can be fully lubricated without contaminating withthe lubricant the gas that is being expanded or compressed.

Another object of the present invention is the provision of areciprocating piston engine in which novel and improved means forcounterbalancing the inertia of the piston are provided.

Still another object of the present invention is the provision of areciprocating piston engine having novel and improved valve-actuatorarrangements.

Finally, it is an object of the present invention to provide areciprocating piston engine that will be relatively simple andinexpensive to manufacture, easy to operate, maintain and repair, andrugged and durable in use.

Other objects and advantages of the present invention will becomeapparent from a consideration of the following description, taken inconnection with the accompanying drawings, in which:

FIGURE 1 is a side elevation with parts broken away of the cylinder andpiston portion of the engine of the present invention;

FIGURE 2 is a cross-sectional view taken on the line 2-2 of FIGURE 1;

FIGURE 3 is a top plan view of the structure of FIG- URE 1;

FIGURE 4 is a cross-sectional view taken on the line 44 of FIGURE 1;

FIGURE 5 is another cross-sectional View, taken on the line 55 of FIGURE1;

FIGURE 6 is a side elevational view of the running gear of the presentinvention;

FIGURE 7 is a top plan view of the structure of FIG- URE 6 with aportion of the top cover plate removed;

FIGURE 8 is a cross-sectional view on the line 88 of FIGURE 6;

FIGURE 9 is a cross-sectional View taken on the line 9-9 of FIGURE 6;

FIGURE 10 is a cross-sectional view taken on the line litill of FIGURE7;

FIGURE 11 is a View similar to FIGURE 10 but taken on the line IIII ofFIGURE 7;

FIGURE 12 is a plan view of a lever element of the invention; and

FIGURE 13 is an elevational View of the lever element of FIGURE 12.

Referring now to the drawings in greater detail, the invention is shownembodied for example in an expansion engine of the reciprocating pistontype, of the general type shown in US. Patents Nos. 2,607,322 and2,678,028, comprising a supporting plate I to which is secured acylindrical casing 3 that forms a portion of the outer casing of theexpansion engine and that houses the cylinder and piston part of theengine. A cylinder 5 is disposed within casing 3 and is spaced from theinner side walls of ice casing 3. If desired, casing 3 may be evacuatedor filled with insulation or both, to reduce heat transfer to or fromthe cylinder and piston. A piston 7 reciprocates in cylinder 5 axiallythereof, and a breather port 9 assures that pressure or vacuum in theclosed end of cylinder 5 will not interfere with movement of piston 7therein.

Cylinder 5 is provided with an inlet port 11 and an outlet port I3communicating between the interior of the cylinder and an inlet conduit15 and an outlet conduit 17, respectively. Conduits I5 and I7 aredisposed outside of cylinder 5 but inside casing 35 and extendlengthwise of easing 3 to what is the lower end thereof in FIGURES 1 and2, where they are secured in fluid-tight relationship with casing 3 bymeans of seals 19. Connections 21 connect conduits I5 and 17 withsources of relatively high and low pressure working fluid, respectively,so that high pressure working fluid flows in through a connection 21 toand through inlet conduit 15 through inlet port II to the interior ofcylinder 5 to power the expansion stroke of the piston, and back outthrough outlet port I3 and outlet conduit I7 and the associatedconnection 21 upon the return or exhaust stroke of piston 7.

An inlet valve 23 and an outlet valve 25 control the admission ofcompressed working fluid to and the exhaust of expanded working fluidfrom inlet port 11 and outlet port 13, respectively. Each of valves 23and 25 is mounted for reciprocation parallel to the axis of cylinder 5on an inlet valve rod 27 and an outlet valve rod 2Q, respectively, thatare greatly elongated and that extend most of the length of easing 3.Rods 27 and 29 extend through and beyond plate I and terminate in endsremote from valves 2?: and 25 that are provided with enlargements 31 forcoaction with the running gear to be described below. Coil compressionsprings 33 encircle valve rods 27 and 29 and act between valves 23 and25 and fixed abutments continuously to urge valves 23 and 25 towardclosed or seated relationship on the margins of inlet and outlet portsI]. and I3. Packing 35 surrounds valve rods 27 and 29 in fluid sealingrelationship substantially to prevent escape of the working fluid.

A piston rod 37 is secured at what is its lower end in FIGURES 1 and 2Within piston 7 and extends axially of cylinder 5 and piston 7 throughand beyond plate 1 and terminates in a clevls 39 by which it is securedto the running gear in a manner to be described below.

The running gear is positioned as best seen in FIGURE 6, above plate Iin that figure and generally on the opposite side of plate I from thecylinder and piston assembly. Housing 41 is secured as by bolting toplate I and includes a removable top cover plate 43 and a removable sidecover plate 45 which are preferably made fluid tight with the remainderof housing 41 by means of appropriate gaskets.

An important feature of the present invention is that the interior ofrunning gear housing 41 is divided by a partition 47 into two chambers49 and 51 and are in fluid-sealed relationship to each other. Chamber 49receives the upper ends of piston rod 37 and valve rods 27 and 29; andof course it is impossible completely to seal chamber 49 from fluidcommunication with the working chamber defined by the cylinder andpiston. Chamber 51, on the other hand, contains the running gear thatneeds lubrication and can be completely lubricated as by beingmaintained substantially full of liquid lubricant. However, becausepartition 47 seals chambers 49 and 51 from each other, the lubricantdoes not get back to chamber 49 and does not contaminate the workingfluid in chamber49, with the result that the working fluid in chamber 49cannot contaminate the working fluid in the working chamber of theexpansion engine. It will of course be appreciated that it isparticularly important to maintain the working fluid free from lubricantand other contaminants in very low temperature expansion operations suchas the expansion of helium to a few degrees above its liquefactiontemperature, for at those very low temperatures any hydrocarbonaceouslubricant contaminating the working fluid would be in solid phase andcould seriously obstruct the operation of the engine.

Among the principal operative elements of the running gear withinhousing 41 are a first rockshaft 53 and second rockshafts 55 and 57.These three rockshafts are all parallel to each other and their axes areall perpendicular to but spaced from the line of reciprocation of piston7.

All three of these rockshafts 53, 55 and 57 also extend through and arejournaled for rotation in and relative to partition 47. As a result,they would offer an opportunity for contaminant to flow from chamber 51to chamber 49 if the pathway for such contaminant were not sealed oif.To seal off this pathway, each of these three rockshafts is providedwith a seal, and the seal for first rockshaft 53 will be described indetail with the understanding that essentially the same seal is used forsecond rockshafts 55 and 57.

The seal for rockshaft 53 includes a sleeve 59 which is fixedly securedas by welding or brazing or the like in partition 47. A further sleeve61 is mounted in a wall of housing 41 and provides a bearing for what isthe lower end of rockshaft 53 as seen in FIGURE 8. A seal 63 extendsbetween and prevents fluid flow between rockshaft 53 and partition 47.Seal '53 includes a flexible sleeve 65 of fluid-impervious material, forexample synthetic rubber, that encompasses rockshaft 53 and is securedat one end to and entirely about rockshaft 53 and at its other end toand entirely about sleeve 59, which in this instance serves as anadaptor portion of partition 4-7 for purposes of securement of sleeve 65to partition 4'7. Sleeve 65 is spaced radially outwardly from rockshaft53, and the annular cylindrical space between sleeve 65 and rockshaft 53is filled at least in part by a plurality of independent floating rings67 that prevent collapse of sleeve 65 under pressure.

As was mentioned above, the seals of second rockshafts 55 and 57 areessentially the same as those of first rockshaft 53; and hence, it willsuffice merely to observe that rockshaft 55 is provided with a journalsleeve 69 and rockshaft 57 is provided with a journal sleeve 71 in whichthe respective second rockshafts are mounted for rotative movement,rockshaft 55 being provided with a flexible seal 73 similar to seal 63and rockshaft 57 being provided with a flexible seal 75 which is alsosimilar to seal 63. A low partition 77 extends part of the way from thebottom toward the top of housing 41 within chamber 51, as is seen bestin FIGURES 7-10; and sleeves 69 and 71, in addition to being fixedlymounted in partition 47 as by welding or brazing or other fluid-tightconnection, also extend through and are supported by partition 77.

First rockshaft 53 is provided with three outwardly extending rockerarms 79, 81 and 83. Rocker arm 79 is on the end of rockshaft 53 withinchamber 49 and is pivotally interconnected with clevis 39 of piston rod37 of the expansion engine, so that upon reciprocation of piston 7 underthe impetus of the expanding working fluid, the moving piston oscillatesrocker arm 79 and causes first rockshaft 53 to have a rocking movementthat drives the entire running gear.

As is seen in FIGURE 11, rocker arm 81 of first rockshaft 53 engageswith a first-class lever 85 journaled for rotation on a shaft 57 that iscarried by partitions 47 and 77 and that is fixed against rotation bymeans of a set screw 89 in partition 77, as is best seen in FIG- URES 9,and 11. lever 85 has a pair of arms that extend generally in oppositedirections from the bearing shaft 87, one of these arms being providedwith a groove 91 in which rocker arm 81 rides as best seen in FIGURES 9and 11, and the other of the arms of lever 35 terminating in a clevis93, best seen in FIGURES 9 and 11. A shaft 95 extends between and ismounted at its ends in the top and bottom plates of housing 41, as bestseen in FIGURE 11, and is parallel to the line of movement of piston 7.A counterweight 9'7 is slidabiy mounted on shaft 95 for verticalreciprocatory movement as seen in FIGURE 11, and a coil compressionspring 99 acts be tween top cover plate 43 and counterweight 97continuously to urge counterweight 97 downwardly as seen in FEGURE ll.Thus, as piston 7 moves downwardly, rockshaft 53 is rocked clockwise asseen in FIGURE 11, so that rocker arm 31 moves downwardly or clockwiseas seen in FIGURE 11, which causes lever 85 to turn counterclockwise sothat clevis 9-3 raises counterweight 97 against the action of spring 99.The mass of counterweight 97 is so selected that it balances piston 7and the parts that move in association with piston '7, so that as piston7 goes down, counterweight 97 goes up, and vice versa. Piston 7 is thusdynamically balanced by a unique lever train that avoids the need forthe crank and pitman assemblies disclosed by the prior art.

The remaining rocker arm 83 of first rockshaft 53 bears in rollingcontact against antifriction roller 1G1 rotatably mounted on a crankpin1% carried by and eccentric to the axis of a crankshaft 195 that isjournaled for rotation in partition '77 in ball bearings 107 and in ballbearings 16? carried by a housing plate 111 removably secured to a sidewall of running gear housing 41. Housing plate 111 also carries anannular seal 113 on the outer side of ball bearings 1&9 that sealsagainst crankshaft to avoid the loss of substantial quantities oflubricant past crankshaft 105 where it leaves running gear housing 41.At its end within chamber 51, crankshaft 1&5 carries a counterweight 115mounted on crankpin 1'93 and extending from crankpin 103 in a directionopposite to the direction in which crankpin 193 extends from crankshaftH15. Counterweight 115 is of a mass and is so positioned that itdynamically balances the eccentric mass of crankpin 193, so thatcrankshaft 135 is dynamically balanced about its axis. The other end 117of crankshaft 105 extends outside running gear housing 4-1 and may beattached to a work-consuming mechanism such as a generator forrecovering the work of isentropic expansion of the working fluid. If theengine is used as a compressor, however, then it is to end 117 ofcrankshaft 105 that the power is applied to reverse the work of themachine and to compress the working fluid. In other words, as anexpansion engine, the piston drives rockshaft 53 which drives crankshaft105; but as a compressor, crankshaft 105 drives rockshaft 53 which inturn drives piston 7.

Cam means are mounted for rotation on crankshaft 105; and as will appearlater, it is these cam means that control the operation of the inlet andoutlet valves of the working chamber of the engine. These cam means havea rotary cam face 119 that encompasses crankshaft 105 and is carried bya split sleeve 121 that releasably grips crankshaft 105. A furtherrotary cam face 123 is provided by the outer periphery of a collar 125that encircles a split portion of sleeve 121. An internallyscrewthreaded nut 127 can be tightened against collar 125 to cause splitsleeve 121 to grip crankshaft 105 to fix the cams on the crankshaft.Each of cam faces 119 and 123 r is provided with appropriate contoursdisposed various distances from the axis of rotation of crankshaft 105,thereby to control the onset and the duration and the termination of theopening and closing movements of the valve. Of course, both of these camfaces can he adjustably rotated relative to crankshaft selectively topredetermine these functions.

Cam face 119 contacts and rocks a rocker arm 129 that is in unitaryassembly with rockshaft 57, on the end of rockshaft 57 that is withinchamber 51, as best seen in FIGURES 9 and 10. At its other end, inchamber 49, rockshaft 57 carries a rocker arm 131 that engages under theenlargement 31 on the upper end of outlet valve rod 29. Thus, when camface 119 rotates so that its outermost portion or highest contourcontacts and rocks rocker arm 123 counterclockwise as seen in FIG- URE10, the rocker arm 131 on the other end of rockshaft 57 will be raisedand will raise outlet valve rod 29 as seen in FIGURE 2, which in turnopens outlet valve 25. When this raised contour of cam face 119 passesbeyond rocker arm 129, rocker arm 129 moves clock- Wise as seen inFIGURE and resumes its former position, which causes the outlet valverod to be released whereupon springs 33 close the outlet valve 25.

The other cam face 123 on collar 125 operates the inlet valve andcontacts a lever 133 journaled for rotation on a shaft 135 parallel toall three rockshafts. Shaft 135 is mounted at its ends in partition 77and the side wall of housing 41 that appears as the bottom wall in FIG-URE 8. As is also seen in FIGURE 8, housing plate 111 can be removed togive access to shaft 135 for replacement or repair. The configuration oflever 133 is best seen in the detail views of this member in FIG- URESl2 and 13. Lever 133 is there seen to have a pair of contact surfaces137 and 139 that are spaced different distances from the axis ofoscillation of lever 133.

In addition to being mounted for oscillation on shaft 135, lever 133 isaxially slidable on shaft 135, and it is intended that one or the otherof contact surfaces 137 and 139 be in contact selectively with cam face123. Selection of the desired contact surface 137 or 133 thus alters thetime at which cam face 123 will act on lever 133 and correspondinglyalters the timing of the operation of the inlet valve. To move lever 133axially along shaft 135, a slot 141 is milled in the end of lever 133opposite the cam contacting surfaces 137 and 139, and an adjustor shaft143 is mounted for rotation on and extends through a side wall ofrunning gear housing 41, as is best seen in FIGURES 8 and 10. Shaft 143is rotatable by manipulation of that portion thereof that is disposedoutside of housing 41, and is provided with an eccentric crankpin 145 onits inner end that is disposed in slot 141. Upon rotation of shaft 143,therefore, lever 133 is slid axially of shaft 135 until the desiredcontact surface 137 or 139 is in operative contact with cam face 123.

Lever 133 is in effect an intermediate rocker arm in the sense that itdoes not directly actuate anything but another rocker arm 147. Thisfurther rocker arm 147 is in unitary assembly with the end of rockshaft55 that is disposed within chamber 51, so that rocking movement of lever133 rocks rocker arm 147 in the same direction as lever 133. It shouldbe noted, however, as is best seen in FIGURE 10, that the distancebetween the axis of shaft 135 and the point of contact of rocker arm 147with lever 133 is substantially less than the distance between the axisof shaft 135 and the point of contact of surface 137 or 139 with camface 123. This means that the movements imparted to lever 133 by camface 123 are transmitted to rocker arm 147 in greatly diminishedmagnitude, so that lever 133 in this sense functions as a second-classlever performing the function of motion reduction. This mechanical trainfrom cam face 123 through lever 133 to rocker arm 147 thus provides ameans for assuring that the movement of rocker arm 147 can be made moreprecise than if rocker arm 147 directly contacted cam face 123.

At its other end, that is, its end within chamber 49, rockshaft 55carries a rocker arm 149 in unitary assembly therewith, rocker arm 149at its end remote from rockshaft 55 engaging under the enlargement 131at the upper end of inlet valve rod 27, so that upon notation of camface 123 clockwise as seen in FIGURE 10, the raised profile of cam face123 rocks lever 133 counterclockwise, which in turn rocks rocker arm 147a lesser 5 angular distance counterclockwise, which in turn raisesrocker arm 149 and lifts inlet valve 23 as seen in FIG- URE 2 to openthe inlet to the working chamber of the expansion engine.

It will therefore be noted that the construction of this inventionprovides a unique running gear characterized in that it can begenerously lubricated without danger of contaminating the working fluidwith lubricant. This is achieved by eliminating the usual crank andpitman connections of the prior art and going instead to a pluralrockshaft system which not only facilitates the provision of seals butalso provides a simple and smoothly operating running gear. This runninggear is further characteriZed by a unique counterweight mechanism. Therockshafts of the running gear also make it possible to operate theinlet and outlet valves of the engine in out-of-phase relationship toeach other and to the operation of the piston, and adjustably to controlthe duration and timing of the operation of the valves relative to eachother and relative to the piston so that any desired timing pattern forthe operation of the engine can be quickly and easily achieved andaccurately maintained.

In view of the foregoing disclosure, therefore, it will be obvious thatall of the initially recited objects of the present invention have beenachieved.

Although the present invention has been described and illustrated inconnection with a preferred embodiment, it is to be understood thatmodifications and variations may be resorted to without departing fromthe spirit of the invention, as those skilled in this art will readilyunderstand. For example, although the rockshafts are disclosed as havingspaced parallel axes, they could instead have the form of concentricsleeves. Such modifications and variations are considered to be withinthe purview and scope of the present invention as defined by theappended claims.

What is claimed is:

1. An engine comprising a cylinder having inlet and outlet valves, apiston reciprocable in the cylinder, a first rockshaft, first meansdrivingly interconnecting the piston and the first rockshaft forconjoint reciprocation of the piston and rocking of the first rockshaft,a second rockshaft, second means interconnecting the first and secondrockshaf-ts for conjoint out-of-phase rocking, third meansinterconnecting the second rockshaft and a said valve to open the valveupon rocking of the second rockshaft, and means sealing said first andthird means from fluid communication with said second means.

2. An expansion engine comprising a cylinder having inlet and outletvalves, a piston reciprocable in the cylinder, a first rockshaft, firstmeans interconnecting the piston and the first rockshaft to rock thefirst rockshaft upon reciprocation of the piston, a second rockshaft,second means interconnecting the first and second rockshafts to rock thesecond rockshaft out-of-phase with the first rockshaft upon rocking ofthe first rockshaft, third means interconnecting the second rockshaftand a said valve to open the valve upon rocking of the second rockshaft,and means sealing said first and third means from fluid communicationwith said second means.

3. An engine comprising a cylinder having inlet and outlet valves, apiston reciprocable in the cylinder, a first rockshaft, first meansdrivingly interconnecting the piston and the first rockshaft forconjoint reciprocation of the piston and rocking of the first rockshaft,a second rockshaft, second means interconnecting the first and secondrockshafts for conjoint out-of-phase rocking, third meansinterconnecting the second rockshaft and a said valve to open the valveupon rocking of the second rockshaft, a housing having a pair ofchambers and a partition sealing the chambers from fluid communicationwith each other, said first and third means being disposed in onechamber and said second means being disposed in the other chamber, thefirst and second rockshafts extending through the partition, and fluidsealing means sealing between the first it and second rockshafts and thepartition to prevent the passage of fluid past the rockshafts betweenthe chambers.

4. An engine as claimed in claim 3, said fiuid sealing means comprisinga flexible sleeve of fluid-impervious material surrounding a rockshaft,the sleeve at one of its ends being sealed to and entirely about itsassociated rockshaft and at its other end being sealed in unitaryassembly with the partition entirely about its associated rockshaft.

5. An expansion engine comprising a cylinder having inlet and outletvalves, a piston reciprocaole in the cylinder, a first rockshaft, firstmeans interconnecting the piston and the first rockshaft to rock thefirst rockshaft upon reciprocation of the piston, a second rockshaft,second means interconnecting the first and second rockshafts to rock thesecond rockshaft out-of-phase with the first rockshafit upon rocking ofthe first rockshaft, third means interconnecting the second rockshaftand a said valve to open the valve upon rocking of the second rockshaft,a housing having a pair of chambers and a partition sealing the chambersfrom fluid communication with each other, said first and third meansbeing disposed in one chamber and said second means being disposed inthe other chamber, the first and second rockshafts extending through thepartition, and fluid sealing means sealing between the first and secondrockshafts and the partition to prevent the passage of fluid past therockshaft between the chambers.

6. An expansion engine as claimed in claim 5, said fluid sealing meanscomprising a flexible sleeve of fluidimpervious material surrounding arockshaft, the sleeve at one of its ends being sealed to and entirelyabout its associated rockshaft and at its other end being sealed inunitary assembly with the partition entirely about its associatedrockshaft.

7. An engine comprising a cylinder having inlet and outlet valves, apiston reciprocable in the cylinder, a first rockshaft, means drivinglyinterconnecting the piston and the first rockshaft for conjointreciprocation of the piston and rocking of the first rockshaft, acrankshaft parallel to the first rockshaft, means drivingly intercon-'meeting the first rockshaft and the crankshaft for conjoint rocking ofthe rockshaft and rotation of the crankshaft, cam means rotatable withthe crankshaft, a second rockshaft, means interconnecting the cam meansand the second rockshaft to rock the second rockshar't upon rotation ofthe cam means, and means interconnecting the second rockshaft and a saidvalve to open the valve upon rocking of the second rockshaft.

8. An engine as claimed in claim 7, said means interconnecting the firstrockshaft and the crankshaft comprising an arm on the rockshaft coactingwith a crankpin on the crankshaft.

9. An expansion engine comprising a cylinder having inlet and outletvalves, a piston reciprocable in the cylinder, a first rockshaft, meansinterconnecting the piston and the first rockshaft to rock the firstrockshaft upon reciprocation of the piston, a crankshaft parallel to thefirst rockshaft, means interconnecting the first rockshaft and thecrankshaft to rotate the crankshaft upon rocking of the first rockshaft,cam means rotatable with the crankshaft, a second reckshaft, meansinterconnecting the cam means and t e second rockshaft to rock thesecond rockshaft upon rotation of the cam means, and meansinterconnecting the second rockshaft and a said valve to open the valveupon rocking of the second rockshaft.

10. An expansion engine as claimed in claim 9, said meansinterconnecting said first rockshaft and the crankshaft comprising anarm on the rockshaft acting against a crankpin on the crankshaft.

11. An engine comprising a cylinder, a piston reciprocable in thecylinder, a rockshaft, means drivingly interconnecting the piston andthe rockshaft for conjoint reciprocation of the piston and rocking ofthe rockshaft, a counterweight reciprocable parallel to the path ofreciprocation of the piston, and means interconnecting the rockshaft andthe counterweight to reciprocate the counterweight in opposite phase tothe piston upon rocking of the rockshaft.

12. An engine as claimed in claim ll, the last-named means comprising afirst-class lever having a pair of arms one of which is driven by therockshaft and the other of which drives the counterweight.

13. An expansion engine comprising a cylinder, a piston reciprocable inthe cylinder, a rockshaft, means interconnecting the piston and therockshaft to rock the rockshaft upon reciprocation of the piston, acounterweight reciprocable parallel to the path of reciprocation of thepiston, and means interconnecting the rockshaft and the counterweight toreciprocate the counterweight in opposite phase to the piston uponrocking of the rockshaft.

14. An expansion engine as claimed in claim 13, the last-named meanscomprising a first-class lever having a pair of arms one of which isdriven by the rockshaft and the other of which drives the counterweight.

References Cited in the file of this patent UNITED STATES PATENTS2,051,534 Skwierawski Aug. 18, 1936 2,235,204 Dadey Mar. 18, 19412,265,306 Orshansky Dec. 9, 1941 2,513,982 William July 4, 19503,063,725 Frey Nov. 13, 1962

1. AN ENGINE COMPRISING A CYLINDER HAVING INLET AND OUTLET VALVES, APISTON RECIPROCABLE IN THE CYLINDER, A FIRST ROCKSHAFT, FIRST MEANSDRIVINGLY INTERCONNECTING THE PISTON AND THE FIRST ROCKSHAFT FORCONJOINT RECIPROCATION OF THE PISTON AND ROCKING OF THE FIRST ROCKSHAFT,A SECOND ROCKSHAFT, SECOND MEANS INTERCONNECTING THE FIRST AND SECONDROCKSHAFTS FOR CONJOINT OUT-OF-PHASE ROCKING, THIRD MEANSINTERCONNECTING THE SECOND ROCKSHAFT AND A SAID VALVE TO OPEN THE VALVEUPON ROCKING OF THE SECOND ROCKSHAFT, AND MEANS SEALING SAID FIRST ANDTHIRD MEANS FROM FLUID COMMUNICATION WITH SAID SECOND MEANS.